Self-Selected or Mandated, Open Access Increases Citation Impact for Higher Quality Research
Figure 5
Interaction between OA and article age.
Over and above the sum of the independent positive effects on citations of OA alone and of age alone, the size of this OA Advantage increases as articles get older. The interaction is illustrated here for the lo/hi (1–4/20+) citation range comparison (model M4) for articles that were from 3 years old (2006) to 7 years old (2002). (The comparison was made in 2009.)